YES Consider the TRS R consisting of the following rewrite rules: f(f(x,y,z),u,f(x,y,v)) -> f(x,y,f(z,u,v)) f(x,y,y) -> y f(x,y,g(y)) -> x f(x,x,y) -> x f(g(x),x,y) -> y The TRS R is transformed (by dropping rewrite rules whose left-hand sides contain a function symbol which does not occur in any right-hand side) into a TRS R' consisting of the following rewrite rules: f(f(x,y,z),u,f(x,y,v)) -> f(x,y,f(z,u,v)) f(x,y,y) -> y f(x,x,y) -> x The TRS R is terminating because R' is match-raise-bounded for RFC#'(R') by 0. A raise-consistent and quasi-deterministic tree automaton compatible with match(R') and RFC#'(R') has - 6 states (1,...,6) - 5 final states (1,2,4,5,6) - 51 transitions: 2 -> 5 4 -> 5 6 -> 5 #_0 -> 4 #_0 -> 5 #_0 -> 6 f_0(2,6,6) -> 5 f_0(4,6,6) -> 5 f_0(6,6,6) -> 5 f_0(2,6,4) -> 5 f_0(4,6,4) -> 5 f_0(6,6,4) -> 5 f_0(2,4,3) -> 5 f_0(4,4,3) -> 5 f_0(6,4,3) -> 5 f_0(2,2,5) -> 5 f_0(2,2,2) -> 5 f_0(4,2,5) -> 5 f_0(4,2,2) -> 5 f_0(6,2,5) -> 5 f_0(6,2,2) -> 5 f_0(2,4,6) -> 5 f_0(4,4,6) -> 5 f_0(6,4,6) -> 5 f_0(2,6,5) -> 5 f_0(2,6,2) -> 5 f_0(4,6,5) -> 5 f_0(4,6,2) -> 5 f_0(6,6,5) -> 5 f_0(6,6,2) -> 5 f_0(2,4,4) -> 5 f_0(4,4,4) -> 5 f_0(6,4,4) -> 5 f_0(2,2,3) -> 5 f_0(4,2,3) -> 5 f_0(6,2,3) -> 5 f_0(2,2,6) -> 5 f_0(2,6,3) -> 5 f_0(4,2,6) -> 5 f_0(4,6,3) -> 5 f_0(6,2,6) -> 5 f_0(6,6,3) -> 5 f_0(2,4,5) -> 5 f_0(2,4,2) -> 5 f_0(4,4,5) -> 5 f_0(4,4,2) -> 5 f_0(6,4,5) -> 5 f_0(6,4,2) -> 5 f_0(2,2,4) -> 5 f_0(4,2,4) -> 5 f_0(6,2,4) -> 5 __________________________________________________________________ TTTbox (0.014 seconds) - April 13, 2007 Source file - /home/ami/mkorp/Testbench/tpdb-3.2/TRS/SK90/4.48.trs